Electric Motorcycle

ABSTRACT

An electric motorcycle comprises a hydraulic pump, an oil passage, a first hydraulic pressure detecting section for detecting a hydraulic pressure in the oil passage, a hydraulic pressure determiner section for determining if the hydraulic pressure is less than a first allowable value, a pump state determiner section for determining if an activation command is output to the hydraulic pump, and a warning output section for outputting a warning signal according to a result of the determination performed by the hydraulic pressure determiner section and a result of the determination performed by the pump state determiner section, wherein the warning signal is not output when the activation command is not output and the hydraulic pressure is less than the first allowable value; and the warning signal is output when the activation command is output and the hydraulic pressure is less than the first allowable value.

TECHNICAL FIELD

The present invention relates to an electric motorcycle including anelectric driving motor as a driving source, or an hybrid electricmotorcycle including an engine in addition to the electric drivingmotor.

BACKGROUND ART

In an exemplary conventional electric motorcycle, a hydraulic pump ofthe electric motorcycle is activated by a driving motor. This hydraulicpump is used to cool and lubricate, for example, a driving system. Inthis electric motorcycle, when a main switch (power supply switch) isturned ON before driving, the driving motor is in an OFF-state and isdeactivated (in a stopped state), and therefore the hydraulic pump isalso deactivated. For this reason, a hydraulic pressure (oil pressure)detector detects a decrease in a hydraulic pressure in an oil passageand a warning light is turned ON. This causes a driver to misunderstandthat there is a failure in the hydraulic pump even in a case where thereis no failure in the hydraulic pump.

In the case of another electric motorcycle in which a hydraulic pump isactivated by a pump motor which is different from the driving motor andoil discharged from this hydraulic pump is used to cool and lubricate adriving system, it is not necessary to activate the hydraulic pump, andthus, the hydraulic pump is deactivated before the driving motor isactivated (when the driving motor is deactivated). In a case where thehydraulic pump is deactivated under a state in which the driving motoris deactivated, a hydraulic pressure detector detects a decrease in ahydraulic pressure in an oil passage and a warning light is turned ON,as in the above case. This causes the driver to misunderstand that thereis a failure in the hydraulic pump even in a case where there is nofailure in the hydraulic pump.

In a case where the warning light is ON after the hydraulic pressuredetector has detected a decrease in the hydraulic pressure in the oilpassage, a seizure of sliding portions in the driving system or abnormalheat generation in the driving motor occurs, if the electric motorcycleis caused to drive under a state in which there is a failure in ahydraulic circuit. Therefore, there exists a problem that this electricmotorcycle cannot drive when it is transported to an inspection place.

Cited Literature 1 (Japanese-Laid Open Patent Application PublicationNo. Hei. 5-330348) discloses a hydraulic control device in a hybridvehicle including a driving motor. This hydraulic control device is ableto improve a performance of an electric motor and increase its life, byefficiently utilizing oil for cooling an engine transmission system asoil for cooling an electric motor.

CITATION LIST Patent Literature

Patent Literature 1: Japanese-Laid Open Patent Application PublicationNo. Hei 5-330348

SUMMARY OF INVENTION Technical Problem

However, in the conventional hydraulic control device disclosed in theabove stated Cited Literature 1, when the hydraulic pump is deactivatedin a normal state and the hydraulic pressure in the oil passage isdecreased, for example, before driving, the warning light which warnsabout the decrease in the hydraulic pressure is not inhibited from beingbe turned ON. In addition, Cited Literature 1 does not disclose a methodof transporting the electric motorcycle in which there is a failure inthe hydraulic circuit including the hydraulic pump to the inspectionplace.

The present invention has been developed to solve the above describedproblem, and an object of the present invention is to provide anelectric motorcycle configured not to display warning information forwarning about a decrease in a hydraulic pressure when a hydraulic pumpis deactivated in a normal state and a hydraulic pressure in an oilpassage is decreased.

Solution to Problem

An electric motorcycle of the present invention comprises a hydraulicpump; an oil passage through which oil forcibly fed by the hydraulicpump flows; a hydraulic pressure detecting device for detecting ahydraulic pressure in the oil passage; a hydraulic pressure determinerunit for determining whether or not a value of the hydraulic pressuredetected by the hydraulic pressure detecting device is less than a firstallowable value; a pump state determiner unit for determining whether ornot an activation command is output to the hydraulic pump; and a warningoutput device for outputting a warning signal according to a result ofthe determination performed by the hydraulic pressure determiner unitand a result of the determination performed by the pump state determinerunit; wherein the warning output device does not output the warningsignal when the pump state determiner unit determines that theactivation command is not output to the hydraulic pump and the hydraulicpressure determiner unit determines that the value of the hydraulicpressure in the oil passage is less than the first allowable value; andthe warning output device outputs the warning signal when the pump statedeterminer unit determines that the activation command is output to thehydraulic pump and the hydraulic pressure determiner unit determinesthat the value of the hydraulic pressure in the oil passage is less thanthe first allowable value.

In accordance with the electric motorcycle of the present invention,even when the value of the hydraulic pressure detected by the hydraulicpressure detecting device is less than the first allowable value, undera state in which the activation command is not output to the hydraulicpump, for example, during starting (before driving), it cannot bedetermined that there is a failure or an abnormality in the hydrauliccircuit including this hydraulic pump. Therefore, the warning outputdevice does not output the warning signal.

This makes it possible to avoid a situation in which a drivermisunderstands that there is a failure or an abnormality in thehydraulic circuit including the hydraulic pump, although it is in anormal state.

However, when the hydraulic pressure in the oil passage is less than thefirst allowable value under a state in which the activation command isoutput to the hydraulic pump, it can be determined that there is afailure or an abnormality in the hydraulic circuit including thishydraulic pump. Therefore, the warning output device outputs the warningsignal.

This allows the driver to accurately recognize that there is a failureor an abnormality in the hydraulic circuit including the hydraulic pump,when there is actually a failure or an abnormality in the hydrauliccircuit including the hydraulic pump.

The electric motorcycle of the present invention may comprise a pumpcontrol unit for controlling activation of the hydraulic pump; whereinthe pump control unit activates the hydraulic pump before driving; andthe hydraulic pressure determiner unit may determine whether or not thevalue of the hydraulic pressure in the oil passage is less than thefirst allowable value, after the hydraulic pump is activated.

Since the pump control unit is configured to be able to activate thehydraulic pump before driving of the electric motorcycle, the hydrauliccircuit including the hydraulic pump can be inspected after thehydraulic pump is activated, for example, before driving. This makes itpossible to avoid a situation in which a failure or an abnormality willoccur in, for example, a driving system such as a driving motor, whenthe electric motorcycle is driving.

In the electric motorcycle of the present invention, the hydraulicpressure detecting device may be a hydraulic sensor; and the hydraulicpressure determiner unit may determine whether or not the value of thehydraulic pressure in the oil passage is less than the first allowablevalue, based on a value of the hydraulic pressure detected by thehydraulic pressure detecting device.

In this configuration, various high-level controls can be implemented byutilizing the value of the hydraulic pressure in the oil passage, whichis detected by the hydraulic sensor, which control cannot not beimplemented by a hydraulic pressure switch which outputs only anON-value or an OFF-value. For example, the value of the hydraulicpressure in the oil passage can be displayed in the display section, ortorque generated in the hydraulic pump can be controlled based on thevalue of the hydraulic pressure. Furthermore, the hydraulic pressuredeterminer unit can set two or more allowable values which are referencevalues used to determine the hydraulic pressure in the oil passage.

In the electric motorcycle of the present invention, the oil passageconnected to an outlet of the hydraulic pump may be provided with afilter, and a hydraulic oil inlet of a driving motor or a hydraulic oilinlet of a transmission in this order from an upstream side; and thehydraulic pressure detecting device may be provided at either one of orboth of a first mounting position which is between the outlet and thefilter and a second mounting position which is between the filter andthe hydraulic oil inlet.

By providing the hydraulic sensor as the hydraulic pressure detectingdevice at the first mounting position or the second mounting position,the hydraulic pressure determiner unit can determine whether thehydraulic pressure at each of the mounting positions is equal to or lessthan a predetermined allowable value set to the first allowable value ora value which is other than the first allowable value. In a case wherethe hydraulic pressure detecting device is provided at the firstmounting position which is between the outlet of the hydraulic pump andthe filter, it can be determined whether or not there is a failure or anabnormality in the hydraulic pump. In a case where the hydraulicpressure detecting device is provided at the second mounting positionwhich is between the filter and the hydraulic oil inlet of the drivingmotor or the transmission, it can be determined whether or not there isa failure or an abnormality in at least one of the hydraulic pump andthe filter. Moreover, when the value of the hydraulic pressure at thefirst mounting position is equal to or greater than the first allowablevalue and the value of the hydraulic pressure at the second mountingposition is less than the first allowable value, in the configuration inwhich the hydraulic sensors are provided at the first mounting positionand the second mounting position, respectively, it can be determinedthat the filter is clogged with foreign matters.

The electric motorcycle of the present invention may comprise a secondhydraulic pressure determiner unit for determining whether or not thevalue of the hydraulic pressure in the oil passage is less than a secondallowable value; and a torque control unit for suppressing torque of adriving motor when the second hydraulic pressure determiner unitdetermines that the value of the hydraulic pressure in the oil passageis less than the second allowable value.

In this configuration, when the value of the hydraulic pressure in theoil passage is less than the second allowable value, the torque controlunit suppresses the torque of the driving motor. Thus, the electricmotorcycle is allowed to drive at a low speed and transported to, forexample, an inspection place, while avoiding occurrence of a failure oran abnormality in components to be lubricated.

In the electric motorcycle of the present invention, the hydraulicpressure detecting device may be a hydraulic sensor; and the torquecontrol unit may decide a degree to which the torque is suppressed basedon the value of the hydraulic pressure detected by the hydraulicpressure detecting device.

In this configuration, the driving motor can be activated by the torquesuppressed properly according to the value of the hydraulic pressuredetected by the hydraulic pressure detecting device.

In the electric motorcycle of the present invention, the oil passage maybe a passage used to lubricate or cool a driving system; and the torquecontrol unit may inhibit the torque from being suppressed, before apredetermined time passes after the hydraulic pump starts to operate.

In this configuration, it becomes possible to avoid a situation in whichthe torque suppressing control is executed even though there is noabnormality in the hydraulic circuit, and thereby the driver'sacceleration feeling during starting gets worse, when the electricmotorcycle starts to move immediately after the hydraulic pump starts tooperate, in a case where some time passes from when the hydraulic pumpstarts to operate until a pressure in the hydraulic circuit reaches aspecified pressure.

Advantageous Effects of Invention

In accordance with an electric motorcycle of the present invention, whena hydraulic pressure in an oil passage is decreased under a state inwhich a hydraulic pump is deactivated in a normal state, warninginformation which warns about a decrease in the hydraulic pressure isnot output. Thus, it becomes possible to avoid a situation in which adriver misunderstands that there is a failure or an abnormality. Inaddition, when there is actually a failure or an abnormality in ahydraulic circuit including a hydraulic pump, the driver can accuratelyrecognize that there is actually a failure or an abnormality in thehydraulic circuit including the hydraulic pump.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a hydraulic circuit including ahydraulic pump and an electric circuit in an electric motorcycleaccording to Embodiment 1 of the present invention.

FIG. 2 is a flowchart showing control of a hydraulic circuit inspectionfunction before starting of a driving motor in the electric motorcycleaccording to Embodiment 1.

FIG. 3 is a flowchart showing control of a torque suppressing functionafter starting of the driving motor in the electric motorcycle accordingto Embodiment 1.

FIG. 4 is a view showing a result of a determination in the flow chartof FIG. 2.

FIG. 5 is a block diagram showing an oil passage including a hydraulicpump and an electric circuit in an electric motorcycle according toEmbodiment 2 of the present invention.

FIG. 6 is a view showing a result of a determination before starting ofthe driving motor in the electric motorcycle according to Embodiment 2,shown in FIG. 5

FIG. 7 is a view showing a result of a determination before starting ofthe driving motor in the electric motorcycle according to Embodiment 2,shown in FIG. 5.

DESCRIPTION OF EMBODIMENTS

Hereinafter, an electric motorcycle according to Embodiment 1 of thepresent invention will be described with reference to FIGS. 1 to 4. Thiselectric motorcycle 1 has a hydraulic circuit inspection function whichenables the display section 12 to display information indicating whetheror not a hydraulic circuit 11 including a hydraulic pump 10 and an oilpassage 14 is in a normal state, and a torque suppressing function whichenables the electric motorcycle 1 to drive properly when it isdetermined that there is an abnormality in the hydraulic circuit 11including the hydraulic pump 10.

The hydraulic circuit inspection function is to inhibit the displaysection 12 from outputting warning information which warns about adecrease in a hydraulic pressure (oil pressure) in the oil passage 14(display section 12 from being turned ON) when the hydraulic pump 10used to cool and lubricate a driving system is deactivated in a normalstate and the hydraulic pressure in the oil passage 14 is decreased,under a state in which the driving motor 13 is deactivated, for example,before driving.

The torque suppressing function is to suppress torque of the drivingmotor 13 by suppressing maximum output torque of the electric motorcycle1 to allow the electric motorcycle 1 to be moved to, for example, aninspection place, even when it is determined that there is anabnormality in the hydraulic circuit 11 including the hydraulic pump 10.This electric motorcycle 1 includes the electric driving motor 13 as adriving source, but may be a hybrid electric motorcycle including anengine in addition to the electric driving motor.

As shown in FIG. 1, the electric motorcycle 1 includes the hydraulicpump 10, a pump motor 15, the oil passage 14, a first hydraulic pressuredetecting section 16, an oil filter 17, an inverter 18, the drivingmotor 13, a transmission 19, an ECU 20, and the display section 12.

The oil passage 14 is provided with the hydraulic pump 10, the firsthydraulic pressure detecting section 16, and the oil filter 17 in thisorder from an upstream side. The oil passage 14 is provided at itsdownstream side with a hydraulic oil inlet of the inverter 18, ahydraulic oil inlet of the driving motor 13, and a hydraulic oil inletof the transmission 19 such that these hydraulic oil inlets are arrangedin parallel. These hydraulic oil inlets are connected to one flowdividing section 22 provided on the oil passage 14.

As shown in FIG. 1, the hydraulic pump 10 is activated by the pump motor15 to forcibly feed oil suctioned from an oil pan 21 to the inverter 18,the driving motor 13, the transmission 19, etc., via the oil passage 14and return the oil to the oil pan 21 via the oil passage 14. Theinverter 18 is cooled by the fed oil, while the driving motor 13 and thetransmission 19 are cooled and lubricated by the fed oil.

The first hydraulic pressure detecting section 16 is, for example, ahydraulic sensor. The first hydraulic pressure detecting section 16 isprovided at a first mounting position which is between an outlet of thehydraulic pump 10 and the oil filter 17 to detect a value of thehydraulic pressure (oil pressure) in a portion of the oil passage 14which is between the outlet of the hydraulic pump 10 and the oil filter17. Instead of the hydraulic sensor, the first hydraulic pressuredetecting section 16 may be a hydraulic pressure switch as will bedescribed later.

The oil filter 17 is configured to remove sludge, abrasion powder,trash, and others from the oil discharged from the hydraulic pump 10.The driving motor 13 is configured to drive the electric motorcycle 1.The inverter 18 is configured to control a rotational speed of thedriving motor 13. The transmission 19 is a device for changing areduction gear ratio of a rotational speed of a wheel with respect to arotational speed of an output shaft of the driving motor 13.

The ECU 20 is an electronic control unit for controlling the electricmotorcycle 1. The ECU 20 is configured to perform various processingaccording to programs pre-stored. The ECU 20 includes a pump controlsection, a first hydraulic pressure determiner section, a pump statedeterminer section, a warning output section, a second hydraulicpressure determiner section, and a torque control section.

The pump control section is configured to control activation of thehydraulic pump 10 and allows the hydraulic pump 10 to be activatedbefore driving of the electric motorcycle 1. The phrase “before drivingof the electric motorcycle 1” refers to, for example, a state in which,a main switch (power supply switch) is ON, and a displacement amount ofan accelerator which is detected by an accelerator sensor is zero (fullyclosed).

The first hydraulic pressure determiner section is configured todetermine whether or not the value of the hydraulic pressure which isdetected by the first hydraulic pressure detecting section 16 is lessthan a first allowable value before driving and during driving. In thepresent embodiment, since the first hydraulic pressure detecting section16 is the hydraulic sensor, it is able to detect the value of thehydraulic pressure. The first hydraulic pressure determiner section isable to determine whether or not the value of the hydraulic pressurewhich is detected by the first hydraulic pressure detecting section 16is less than the first allowable value.

The pump state determiner section is configured to determine whether ornot the pump control section is outputting an activation command to thehydraulic pump 10.

The warning output section is configured to output a warning signal tothe display section 12 connected to the ECU 20 to cause the displaysection 12 to display specified warning information, according to aresult of the determination performed by the first hydraulic pressuredeterminer section and a result of the determination performed by thepump state determiner section. The display section 12 does not displaywarning information corresponding to the warning signal when the warningoutput section is not outputting the warning signal.

For example, when the pump control section is not outputting theactivation command to the hydraulic pump 10, and the first hydraulicpressure determiner section determines that the value of the hydraulicpressure in the oil passage 14 is less than the first allowable value,it is determined that the hydraulic circuit 11 including the hydraulicpump 10 and the oil passage 14, shown in FIG. 1, is in a normal state,and therefore the warning output section does not output the warningsignal. On the other hand, when the pump control section is outputtingthe activation command to the hydraulic pump 10, and the first hydraulicpressure determiner section determines that the value of the hydraulicpressure in the oil passage 14 is less than the first allowable value,it is determined that the hydraulic circuit 11 is in an abnormal state,and the warning output section outputs the warning signal. The abnormalstate of the hydraulic circuit 11 may include, for example, clogging ofthe oil filter 17, and a leakage of the oil which is caused by damagesto the oil passage 14 (pipe) constituting the hydraulic circuit 11.

When the pump control section is outputting the activation command tothe hydraulic pump 10, and the first hydraulic pressure determinersection determines that the value of the hydraulic pressure in the oilpassage 14 is equal to or greater than the first allowable value, it canbe determined that the hydraulic circuit 11 including the hydraulic pump10 is in a normal state. Therefore, the warning output section does notoutput the warning signal and the display section 12 does not displaythe warning information. This allows the driver to accurately recognizethat the hydraulic circuit 11 including the hydraulic pump 10 is in anormal state.

The display section 12 has display parts corresponding to, for example,the hydraulic pump 10, the oil passage 14, the first hydraulic pressuredetecting section 16 and the oil filter 17, respectively. When thewarning signal is input, the corresponding display part is turned ON.The above is the hydraulic circuit inspection function.

Next, the torque suppressing function of the ECU 20 of FIG. 1 will bedescribed. The torque suppressing function is implemented by the firsthydraulic pressure determiner section, a second hydraulic pressuredeterminer section, and the torque control section.

The second hydraulic pressure determiner section is configured todetermine whether or not the value of the hydraulic pressure in the oilpassage 14 which is detected by the first hydraulic pressure detectingsection 16 of FIG. 1 is less than a second allowable value. The secondallowable value is smaller than, for example, the first allowable value.

The torque control section is configured to suppress the torque of thedriving motor 13 when the first hydraulic pressure determiner sectiondetermines that the hydraulic pressure in the oil passage 14 is lessthan the first allowable value, during driving. The second hydraulicpressure determiner section determines whether or not the hydraulicpressure is less than the second allowable value. Based on a result ofthe determination, the torque control section sets output torque suchthat a degree to which the torque is suppressed is made different

Next, the operation of the electric motorcycle 1 configured as describedabove will be described with reference to FIGS. 1 to 4. FIG. 2 is aflowchart showing control of the hydraulic circuit inspection functionbefore starting (driving) of the driving motor 13. FIG. 3 is a flowchartshowing control of the torque suppressing function after starting(during driving) of the driving motor 13.

It is assumed that in the control of the hydraulic circuit inspectionfunction before starting of the driving motor 13 of FIG. 2, for example,the electric motorcycle 1 is now starting (before driving), the mainswitch (power supply switch) is ON, and the displacement amount of theaccelerator which is detected by the accelerator sensor is zero (fullyclosed). The pump control section is not activating the hydraulic pump10, and therefore, the pump state determiner section determines that thepump control section is not outputting the activation command to thehydraulic pump 10.

Under this state, the value of the hydraulic pressure in the oil passage14 which is detected by the first hydraulic pressure detecting section16 of FIG. 1 is input to the ECU 20 as a detected hydraulic pressuresignal (step S100). The first hydraulic pressure determiner sectiondetermines whether or not the value of the hydraulic pressure which isdetected by the first hydraulic pressure detecting section 16 is lessthan the first allowable value (step S102). When the first hydraulicpressure determiner section determines that the value of the hydraulicpressure is equal to or greater than the first allowable value, i.e., aresult of the determination is “NO”, the warning output section outputsa warning signal indicating that either one of or both of the firsthydraulic pressure detecting section 16 and the hydraulic circuit 11(including the hydraulic pump 10) is/are in abnormal state(s), to thedisplay section 12, to cause the display unit 12 to display informationindicating that either one of or both of the first hydraulic pressuredetecting section 16 and the hydraulic circuit 11 is/are in abnormalstate(s) (step S104).

In step S102, when the first hydraulic pressure determiner sectiondetermines that the value of the hydraulic pressure in the oil passage14 is less than the first allowable value, i.e., a result of thedetermination is “YES”, under a state in which the pump control sectionis not outputting the activation command to the hydraulic pump 10, thewarning output section does not output the warning signal at this pointof time. It should be noted that at this point of time, it is determinedthat at least the first hydraulic pressure detecting section 16 is in anormal state (this is not shown).

In step S102, when the first hydraulic pressure determiner sectiondetermines that the value of the hydraulic pressure is less than thefirst allowable value, i.e., a result of the determination is “YES”, thepump control section activates the hydraulic pump 10 (step S106). Then,after a passage of predetermined time (e.g., about 5 seconds), the firsthydraulic pressure determiner section determines whether or not thevalue of the hydraulic pressure which is detected by the first hydraulicpressure detecting section 16 is less than the first allowable value(step S108, step S110). When the first hydraulic pressure determinersection determines that the value of the hydraulic pressure is equal toor greater than the first allowable value, i.e., a result of thedetermination is “NO”, it can be determined that the hydraulic circuit11 including the hydraulic pump 10 and the first hydraulic pressuredetecting section 16 are in normal states. Therefore, the warning outputsection does not output the warning signal, and the display section 12is OFF, which indicates that the hydraulic circuit 11 and the firsthydraulic pressure detecting section 16 are in normal states (stepS112).

In the above described manner, the driver can accurately recognize thatthe first hydraulic pressure detecting section 16 and the hydrauliccircuit 11 including the hydraulic pump 10, shown in FIG. 1, are innormal states during starting (before driving).

In step S110, when the first hydraulic pressure determiner sectiondetermines that the value of the hydraulic pressure is less than thefirst allowable value, i.e., a result of the determination is “YES”, thewarning output section outputs a warning signal indicating that thehydraulic circuit 11 including the hydraulic pump 10 is in an abnormalstate, to the display section 12, to cause the display section 12 todisplay information indicating that the hydraulic circuit 11 includingthe hydraulic pump 10 is in an abnormal state (step S114).

Since it has been determined as “YES” and that the first hydraulicpressure detecting section 16 is in a normal state, in step S102, awarning signal corresponding to the first hydraulic pressure detectingsection 16 is not output, at this time.

As described above, even when the value of the hydraulic pressuredetected by the first hydraulic pressure detecting section 16 is lessthan the first allowable value (YES in step 102), in the case where theactivation command is not output to the hydraulic pump 10, for example,during starting (before driving), it cannot be determined that there isa failure or an abnormality in the hydraulic circuit 11 including thehydraulic pump 10. Therefore, the warning output section does not outputthe warning signal.

This makes it possible to avoid a situation in which the drivermisunderstands that there is a failure or an abnormality in thehydraulic circuit 11 including the hydraulic pump 10, although it is ina normal state.

On the other hand, when the value of the hydraulic pressure in the oilpassage 14 is less than the first allowable value under a state in whichthe activation command is output to the hydraulic pump 10 (YES in stepS110), it can be determined that there is a failure or an abnormality inthe hydraulic circuit 11 including the hydraulic pump 10. Therefore, thewarning output section outputs the warning signal.

This allows the driver to accurately recognize that there is a failureor an abnormality in the hydraulic circuit 11 including the hydraulicpump 10, when there is actually a failure or an abnormality in thehydraulic circuit 11 including the hydraulic pump 10.

Since the pump control section is configured to be able to activate thehydraulic pump 10 before driving of the electric motorcycle 1 (stepS106), the hydraulic circuit 11 including the hydraulic pump 10 can beinspected before driving. This makes it possible to avoid a situation inwhich a failure or an abnormality will occur in, for example, thedriving system such as the driving motor 13, when the electricmotorcycle 1 is driving.

Next, the control of the torque suppressing function after starting(during driving) of the driving motor 13 will be described withreference to a flowchart of FIG. 3.

It is assumed that in the control of the torque suppressing function ofFIG. 3, it is determined that the hydraulic circuit 11 including thehydraulic pump 10 and the first hydraulic pressure detecting section 16are now in normal states, respectively, by the hydraulic circuitinspection function of FIG. 2.

Initially, in step S200, when the pump state determiner sectiondetermines whether or not the pump control section is outputting theactivation command to the hydraulic pump 10 under a state in which thepump control section is activating the hydraulic pump 10, and determinesthat the pump control section is outputting the activation command tothe hydraulic pump 10 (hydraulic pump 10 is activated), i.e., a resultof the determination “YES”, the first hydraulic pressure determinersection determines whether or not the value of the hydraulic pressuredetected by the first hydraulic pressure detecting section 16 is lessthan the first allowable value (step S202, step S204).

When the first hydraulic pressure determiner section determines that thevalue of the hydraulic pressure is equal to or greater than the firstallowable value, i.e., a result of the determination “NO”, in step S204,it is determined that the hydraulic circuit 11 including the hydraulicpump 10 and the first hydraulic pressure detecting section 16 are innormal states during driving, the warning output section does not outputthe warning signal, and the display section 12 is OFF, indicating thatthe hydraulic circuit 11 including the hydraulic pump 10 and the firsthydraulic pressure detecting section 16 are in normal states (stepS206).

When the first hydraulic pressure determiner section determines that thevalue of the hydraulic pressure is less than the first allowable value,i.e., a result of the determination “YES”, in step S204, the secondhydraulic pressure determiner section determines whether or not thevalue of the hydraulic pressure detected by the first hydraulic pressuredetecting section 16 is less than the second allowable value smallerthan the first allowable value (step S210), after a passage of set time(e.g., about 5 seconds are set) required to flow the hydraulic oil tothe hydraulic circuit 11 (step S208).

When the second hydraulic pressure determiner section determines thatthe value of the hydraulic pressure is equal to or greater than thesecond allowable value, i.e., a result of the determination “NO”, instep S210, it is determined that the hydraulic circuit 11 including thehydraulic pump 10 and the like are in abnormal states, and the torquecontrol section executes first torque suppressing control (medium torquesuppressing control) for the driving motor 13 (step S212). At this time,the display section 12 displays information indicating that thehydraulic circuit 11 including the hydraulic pump 10 and the like are inabnormal states and the first torque suppressing control is executed.The first torque suppressing control refers to control executed so thatmaximum output torque which can be output from the driving motor 13becomes pre-set medium torque which is smaller than normal (rated)maximum output torque.

On the other hand, when the second hydraulic pressure determiner sectiondetermines that the value of the hydraulic pressure is less than thesecond allowable value, i.e., a result of the determination “YES”, instep S210, it is determined that the hydraulic circuit 11 including thehydraulic pump 10, and the like are in abnormal states, and the torquecontrol section executes second torque suppressing control (low torquesuppressing control) for the driving motor 13 (step S214). At this time,the display section 12 displays information indicating that thehydraulic circuit 11 including the hydraulic pump 10, and the like arein abnormal states and the second torque suppressing control isexecuted. The second torque suppressing control refers to controlexecuted so that the maximum output torque which can be output from thedriving motor 13 becomes pre-set low torque which is smaller than themedium torque.

In accordance with the torque suppressing function shown in theflowchart of FIG. 3, when the value of the hydraulic pressure in the oilpassage 14 is between the first allowable value and the second allowablevalue (step S212), or when the value of the hydraulic pressure is lessthan the second allowable value (step S214), the torque control sectionsuppresses the maximum output torque of the driving motor 13. Thisallows the electric motorcycle 1 to drive at a medium speed or a lowspeed to be transported to, for example, an inspection place, whileavoiding occurrence of a failure or an abnormality in the components tobe lubricated, such as the driving system.

The torque control section is able to activate the driving motor 13 byproperly executing the first torque suppressing control (medium torquesuppressing control) or the second torque suppressing control (lowtorque suppressing control), depending on whether the value of thehydraulic pressure detected by the first hydraulic pressure detectingsection 16 falls in a range between the first allowable value and thesecond allowable value, or a range which is less than the secondallowable value.

After a passage of the set time required to flow the hydraulic oil tothe hydraulic circuit 11 (step S208), the first hydraulic pressuredeterminer section determines whether or not the value of the hydraulicpressure detected by the first hydraulic pressure detecting section 16is less than the first allowable value (step S204). Therefore, when theelectric motorcycle 1 starts to move immediately after the hydraulicpump 10 starts to operate, in a case where some time passes from whenthe hydraulic pump 10 starts to operate until a pressure in thehydraulic circuit 11 reaches a specified pressure, it becomes possibleto avoid a situation in which the torque suppressing control is executedeven though there is no abnormality in the hydraulic circuit 11, andthereby the driver's acceleration feeling during starting gets worse.

The use of the hydraulic sensor as the first hydraulic pressuredetecting section 16 enables various high-level control by utilizing thevalue of the hydraulic pressure in the oil passage 14 which is detectedby the hydraulic sensor, which control cannot not be implemented by ahydraulic pressure switch which outputs only an ON-value or anOFF-value.

For example, as shown in FIG. 3, the first hydraulic pressure determinersection can set two or more allowable values, i.e., the first allowablevalue and the second allowable value as allowable values used todetermine the hydraulic pressure in the oil passage 14. The displaysection 12 can display the value of the hydraulic pressure in the oilpassage 14. Or, the torque generated in the pump motor 15 can becontrolled based on the value of the hydraulic pressure. By controllingthe torque generated in the pump motor 15 in this way, the hydraulicpressure in the oil passage 14 can be increased up to a proper pressure,or can be decreased to reduce a load of the pump motor 15.

As shown in step S204 and step S210 of FIG. 3, the first and secondhydraulic pressure determiner sections can set two or more allowablevalues which are reference values used to determine the hydraulicpressure in the oil passage 14.

Although the hydraulic sensor is used as the first hydraulic pressuredetecting section 16 of FIG. 1, the hydraulic pressure switch may beused in place of the hydraulic sensor. In this case, a second hydraulicpressure switch which is different from the first hydraulic pressureswitch, may be attached to the oil passage 14 to detect whether thevalue of the hydraulic pressure in the oil passage 14 is less than thesecond allowable value, and may output a detection signal indicatingthat the hydraulic pressure in the oil passage 14 is less than thesecond allowable value, in step S210 of FIG. 3.

FIG. 4 shows results of inspection performed by the hydraulic circuitinspection function of FIG. 2. When the value of the hydraulic pressurein the hydraulic circuit 11 which is detected by the first hydraulicpressure detecting section 16 is less than the first allowable value(case of (1)), in cases where the hydraulic pump 10 is deactivated(cases (1) and (2)), it is determined that the first hydraulic pressuredetecting section 16 is in a normal state, but it is not clear as towhether or not the hydraulic circuit 11 is in a normal state. Therefore,the display section 12 does not display warning information. On theother hand, when the value of the hydraulic pressure in the hydrauliccircuit 11 which is detected by the first hydraulic pressure detectingsection 16 is equal to or greater than the first allowable value (caseof (2)), it is determined that either one or both of the first hydraulicpressure detecting section 16 and the hydraulic circuit 11 is/are inabnormal state(s). The display section 12 displays warning informationindicating that either one or both of the first hydraulic pressuredetecting section 16 and the hydraulic circuit 11 is/are in abnormalstate(s).

When the value of the hydraulic pressure in the hydraulic circuit 11which is detected by the first hydraulic pressure detecting section 16is equal to or greater than the first allowable value (case of (3)), incases where the hydraulic pump 10 is activated (cases (3) and (4)), itis determined that the first hydraulic pressure detecting section 16 andthe hydraulic circuit 11 (including the hydraulic pump 10) are in normalstates, and the display section 12 does not display warning informationand is OFF. On the other hand, when the value of the hydraulic pressurein the hydraulic circuit 11 which is detected by the first hydraulicpressure detecting section 16 is less than the first allowable value(case of (4)), it is determined that either the first hydraulic pressuredetecting section 16 or the hydraulic circuit 11 (including thehydraulic pump 10) is in an abnormal state. The display section 12displays warning information indicating that the first hydraulicpressure detecting section 16 or the hydraulic circuit 11 is in anabnormal state.

Next, an electric motorcycle according to Embodiment 2 will be describedwith reference to FIGS. 5 to 7. The electric motorcycle 1 of Embodiment2 of FIG. 5 is different from the electric motorcycle 1 of Embodiment 1of FIG. 1 in that in Embodiment 1 of FIG. 1, the first hydraulicpressure detecting section 16 is attached to the oil passage 14 at thefirst mounting position which is between the outlet of the hydraulicpump 10 and the oil filter 17, while in Embodiment 2 of FIG. 5, thefirst hydraulic pressure detecting section 16 is attached to the oilpassage 14 at the first mounting position which is between the outlet ofthe hydraulic pump 10 and the oil filter 17, and a second hydraulicpressure detecting section 23 is attached to the oil passage 14 at asecond mounting position which is between the oil filter 17 and the flowdividing section 22 for feeding the hydraulic oil to the hydraulic oilinlet of the inverter 18, the hydraulic oil inlet of the driving motor13, and the hydraulic oil inlet of the transmission 19.

The two hydraulic pressure detecting sections, which are the firsthydraulic pressure detecting section 16 and the second hydraulicpressure detecting section 23, are provided in order to individuallydetect an abnormality in the hydraulic pump 10 and an abnormality in theoil filter 17 before starting (driving) as shown in FIGS. 6 and 7, inaddition to performing the above stated inspection function of thehydraulic circuit of Embodiment 1. In the present embodiment, anabnormality in the first hydraulic pressure detecting section 16 and anabnormality in the second hydraulic pressure detecting section 23 can beindividually detected.

FIG. 6 shows an inspection method for determining whether the firsthydraulic pressure detecting section 16 and the second hydraulicpressure detecting section 23 are in a normal state or in an abnormalstate, during starting (before driving). When the hydraulic pump 10 isnot activated and each of the first hydraulic pressure detecting section16 and the second hydraulic pressure detecting section 23 is detectingthe value of the hydraulic pressure which is less than the firstallowable value (case (1)), it can be determined that both of the firsthydraulic pressure detecting section 16 and the second hydraulicpressure detecting section 23 are in normal states. The display section12 does not display warning information corresponding to the firsthydraulic pressure detecting section 16 and the second hydraulicpressure detecting section 23 determined as normal states, and thereforeis OFF.

On the other hand, when either one or both of the first hydraulicpressure detecting section 16 and the second hydraulic pressuredetecting section 23 is/are detecting the value of the hydraulicpressure which is/are equal to or greater than the first allowablevalue, it can be determined that the hydraulic pressure detectingsection(s) which has (have) detected the value is/are in abnormalstate(s) (cases (2), (3), (4)). The display section 12 displays a resultof this determination and is turned ON. The first hydraulic pressuredeterminer section determines whether or not either one or both of thefirst and second hydraulic pressure detecting sections 16, 23 is/aredetecting the hydraulic pressure which is less than the first allowablevalue.

FIG. 7 shows a method of inspection performed to determine whether eachof the hydraulic pump 10 and the oil filter 17 is in a normal state orin an abnormal state, during starting (before driving), subsequently toa case where it is determined that both of the first hydraulic pressuredetecting section 16 and the second hydraulic pressure detecting section23 are in normal states, in the example of FIG. 6. When the hydraulicpump 10 is activated and both of the first hydraulic pressure detectingsection 16 and the second hydraulic pressure detecting section 23 aredetecting the value of the hydraulic pressure which is equal to orgreater than the first allowable value (case (1)), it can be determinedthat both of the hydraulic pump 10 and the oil filter 17 are in normalstates. The display section 12 does not display warning informationcorresponding to the hydraulic pump 10 and the oil filter 17 determinedas normal states, and therefore is OFF.

On the other hand, when the first hydraulic pressure detecting section16 is detecting the value of the hydraulic pressure which is equal to orgreater than the first allowable value, but the second hydraulicpressure detecting section 23 is detecting the value of the hydraulicpressure which is less than the first allowable value, as in case (2) ofFIG. 7, it is determined that the hydraulic pump 10 is in a normal statebut the oil filter 17 is in an abnormal state, due to clogging, or thelike. The display section 12 displays information indicating that thereis an abnormality in the oil filter 17, as a result of thedetermination, by turning on the display part corresponding to the oilfilter 17.

When both of the first hydraulic pressure detecting section 16 and thesecond hydraulic pressure detecting section 23 are detecting the valueof the hydraulic pressure which is less than the first allowable value,as in case (3) of FIG. 7, it is determined that the hydraulic pump 10 isin an abnormal state. The display section 12 displays informationindicating that there is an abnormality in the hydraulic pump 10, as aresult of the determination, by turning on the display partcorresponding to the hydraulic pump 10. However, it cannot be determinedwhether the oil filter 17 is in a normal state or in an abnormal state,and therefore the display part 12 corresponding to the oil filter 17 isOFF.

Although in Embodiment 2, the hydraulic sensors are used as the firsthydraulic pressure detecting section 16 and the second hydraulicpressure detecting section 23 of FIG. 5, the hydraulic pressure switchesmay be used in place of the hydraulic sensors. In this case, asdescribed in Embodiment 1, the second hydraulic pressure switch which isdifferent from the first hydraulic pressure switch, may be attached tothe oil passage 14 to detect whether or not the value of the hydraulicpressure in the oil passage 14 is less than the second allowable value,and may output a detection signal indicating whether or not the value ofthe hydraulic pressure in the oil passage 14 is less than the secondallowable value, in step S210 of FIG. 3.

Although in the above described embodiments, the first torquesuppressing control (step S212) and the second torque suppressingcontrol (step S214) are performed in the control performed by the torquesuppressing function of FIG. 3, only either one of the first torquesuppressing control and the second torque suppressing control mayalternatively be performed. In a further alterative, torque suppressingcontrol at three or more levels may be performed. For example, torquesuppressing control at three levels, which are medium torque suppressingcontrol, low torque suppressing control, and super-low torquesuppressing control, may be performed.

Although the allowable value of the hydraulic pressure in step S102 ofFIG. 2 matches the allowable value of the hydraulic pressure in stepS204 of FIG. 3 as the first allowable value, these allowable values maybe different from each other.

As shown in FIG. 3, the torque control section of the above describedembodiments executes control such that the maximum output torque becomesthe first (medium) torque when the value of the hydraulic pressure inthe oil pressure 14 which is detected by the first hydraulic pressuredetecting section 16 falls in the range between the first allowablevalue and the second allowable value (step S212), and executes controlsuch that the maximum output torque becomes the second (low) torque whenthe value of the hydraulic pressure in the oil pressure 14 which isdetected by the first hydraulic pressure detecting section 16 is lessthan the second allowable value (step S214). Alternatively, the torquecontrol section may execute control such that the maximum output torquedecreases as the value of the hydraulic pressure in the oil passage 14which is detected by the first hydraulic pressure detecting section 16decreases.

Or, in a case where the maximum output torque corresponding to theabnormal state is set by multiplying normal (rated) maximum outputtorque by a torque suppressing coefficient a (0<a<1), the torquesuppressing coefficient a may be set such that it decreases as the valueof the hydraulic pressure in the oil passage 14 which is detected by thefirst hydraulic pressure detecting section 16 decreases. In thissetting, the degree to which the torque is suppressed can be increasedaccording to the degree to which the hydraulic pressure decreases. Thus,the driving motor 10 can be controlled properly. In this way, also, theelectric motorcycle 1 is allowed to drive at a low speed and transportedto, for example, the inspection place, while avoiding occurrence of afailure or an abnormality in the components to be lubricated.

Although in the above described embodiments, the hydraulic pump 10 isactivated by the pump motor 15 which is different from the driving motor13, it may be activated by the driving motor 13. In this case, forexample, a clutch mechanism may be provided to allow the driving motor13 to activate both of the wheel and the hydraulic pump 10 or only thehydraulic pump 10.

Although in the above described embodiments, the first hydraulicpressure detecting section 16 is attached to the oil passage 14 at thefirst mounting position which is between the hydraulic pump 10 and theoil filter 17, as shown in FIG. 1, it may be attached to the oil passage14 at a position other than the first mounting position. For example,the first hydraulic pressure detecting section 16 may be attached to theoil passage 14 at the second mounting position which is between the oilfilter 17 and the flow dividing section 22.

INDUSTRIAL APPLICABILITY

As should be appreciated from the above, the electric motorcycle of thepresent invention can achieve remarkable advantages in that when ahydraulic pump is deactivated in a normal state and a hydraulic pressurein an oil passage is decreased, for example, before driving, warninginformation which warns about a decrease in the hydraulic pressure isnot output, and is suitably applied to such an electric motorcycle.

REFERENCE CHARACTERS LIST

1 electric motorcycle

10 hydraulic pump

11 hydraulic circuit

12 display section

13 driving motor

14 oil passage

15 pump motor

16 first hydraulic pressure detecting section

17 oil filter

18 inverter

19 transmission

20 ECU

21 oil pan

22 flow dividing section

23 second hydraulic pressure detecting section

1. An electric motorcycle comprising: a hydraulic pump; an oil passagethrough which oil forcibly fed by the hydraulic pump flows; a hydraulicpressure detecting device for detecting a hydraulic pressure in the oilpassage; a hydraulic pressure determiner unit for determining whether ornot a value of the hydraulic pressure detected by the hydraulic pressuredetecting device is less than a first allowable value; a pump statedeterminer unit for determining whether or not an activation command isoutput to the hydraulic pump; and a warning output device for outputtinga warning signal according to a result of the determination performed bythe hydraulic pressure determiner unit and a result of the determinationperformed by the pump state determiner unit; wherein the warning outputdevice does not output the warning signal when the pump state determinerunit determines that the activation command is not output to thehydraulic pump and the hydraulic pressure determiner unit determinesthat the value of the hydraulic pressure in the oil passage is less thanthe first allowable value; and wherein the warning output device outputsthe warning signal when the pump state determiner unit determines thatthe activation command is output to the hydraulic pump and the hydraulicpressure determiner unit determines that the value of the hydraulicpressure in the oil passage is less than the first allowable value. 2.The electric motorcycle according to claim 1, comprising: a pump controlunit for controlling activation of the hydraulic pump; wherein the pumpcontrol unit activates the hydraulic pump before driving; and whereinthe hydraulic pressure determiner unit determines whether or not thevalue of the hydraulic pressure in the oil passage is less than thefirst allowable value, after the hydraulic pump is activated.
 3. Theelectric motorcycle according to claim 1, wherein the hydraulic pressuredetecting device is a hydraulic sensor; and wherein the hydraulicpressure determiner unit determines whether or not the value of thehydraulic pressure in the oil passage is less than the first allowablevalue, based on a value of the hydraulic pressure detected by thehydraulic pressure detecting device.
 4. The electric motorcycleaccording to claim 1, wherein the oil passage connected to an outlet ofthe hydraulic pump is provided with a filter, and a hydraulic oil inletof a driving motor or a hydraulic oil inlet of a transmission in thisorder from an upstream side; and wherein the hydraulic pressuredetecting device is provided at either one of or both of a firstmounting position which is between the outlet of the hydraulic pump andthe filter and a second mounting position which is between the filterand the hydraulic oil inlet.
 5. The electric motorcycle according toclaim 1, comprising: a second hydraulic pressure determiner unit fordetermining whether or not the value of the hydraulic pressure in theoil passage is less than a second allowable value; and a torque controlunit for suppressing torque of a driving motor when the second hydraulicpressure determiner unit determines that the value of the hydraulicpressure in the oil passage is less than the second allowable value. 6.The electric motorcycle according to claim 5, wherein the hydraulicpressure detecting device is a hydraulic sensor; and wherein the torquecontrol unit decides a degree to which the torque is suppressed based onthe value of the hydraulic pressure detected by the hydraulic pressuredetecting device.
 7. The electric motorcycle according to claim 5,wherein the oil passage is a passage used to lubricate or cool a drivingsystem; and wherein the torque control unit inhibits the torque frombeing suppressed, before a predetermined time passes after the hydraulicpump starts to operate.